Asthma is a common chronic disease worldwide with an estimated 300 million affected individuals. In analyses of economic burden of asthma, apart from direct medical costs including hospital admissions and cost of medications, indirect, non-medical costs such as time lost from work account for a considerable part. For all but the most severe patients, the ultimate goal is to prevent symptoms, minimize morbidity from acute episodes, and prevent functional and psychological morbidity to provide a near healthy lifestyle. Although the symptoms can be controlled by drug treatment in most patients, effective low-risk, non-drug approaches such as acupuncture could constitute a significant advance in asthma management. The purpose of this study is to assess whether acupuncture is effective in the treatment of chronic asthma.